I have a double type column in impala
while I am trying to cut it upto some decimal places
I got this error
ERROR: AnalysisException: No matching function with signature: truncate(DOUBLE, TINYINT).
e.g select truncate(cast(0.4893617021276596 as double),7);
any workaround will be welcome
You can use round():
select round(col, 6)
If you actually want a truncate, then subtract 0.0000005:
select round(col - 0.0000005, 6)
Using the DECIMAL type, it is possible to represent numbers with greater precision than the FLOAT or DOUBLE types can represent.
The maximum allowed precision and scale of the DECIMAL type are both 38.
Precision is the total number of digits, regardless of the location of the decimal point.
Scale is the number of digits after the decimal place.
To represent the number 8.54 without a loss of precision, you would need a
DECIMAL type with precision of at least 3, and scale of at least 2.
Example:
Note that the DECIMAL(17,16) type means there is a total of 17 digits, with 16 of them after the decimal point.
DECIMAL(17,16) 3.1415926535897932
You could ALTER your table with DECIMAL type as follow:
ALTER TABLE my_table CHANGE field field DECIMAL(precision, scale);
or as suggest #Gordon Linoff, you could use round() function.
Related
I have a column with datatype float in Teradata. I want to find the Maximum precision and scale for that column.
Note: My column's scale part has more than 10 digits in most of the places.
Sample Data
123.12321323002
13123213.13200003
33232.213123001
The output I need is
Precsion 19 (scale + length of 13123213) and scale is 11 (length of 12321323002)
or
8 (length of 13123213), 11 (length of 12321323002).
I tried to find them buy converting the column as varchar and splitting them based on the '.' and make the integer and fractional part as 2 columns and then finding the max length of 2 columns. But when I'm select the data, Teradata rounds off the scale part. So after that, if I convert them as char, I'm getting lesser value for scale part.
For example:
org data: 1234.12312000123101
data when I select from Teradata: 1234.12312000123
This is a bit long for a comment.
Teradata uses the IEEE format for real/float values. This gives 15-17 digits of precision. Alas, you need 19 digits, so the values you want are not being stored in the database. You cannot recover them.
What you can do is fix the database, so it uses numeric/decimal/number. This supports what you want: NUMERIC(19, 11). You would then need to reload the data so it is correctly stored in the database.
When you need high precision without predefined scale simply switch to the NUMBER datatype, which is a mixture of DECIMAL and FLOAT.
Exact numeric, at least 38 digits precision, no predefined scale, range of 1E-130 .. 1E125.
Float on steroids :-)
I would like to remove zeros after two decimal places in DB2. I have more than 1000 rows for this column
For example
3.6900 needs to be converted to 3.69
I used cast in the query after my research and it gave me the correct result but I would like to understand what is DECIMAL(12,2) and how does this work ? Is there any better way to eliminate zeros?
SELECT CAST(CG.RATE AS DECIMAL(12,2)) AS test from fd.OFFERS CG
Please let me know.
what is DECIMAL(12,2) and how does this work?
The DECIMAL data type represents numbers with a specified decimal precision. You can read a description of the numeric data types:
A DECIMAL number is a packed decimal number with an implicit decimal point. The position of the decimal point is determined by the precision and the scale of the number. The scale, which is the number of digits in the fractional part of the number, cannot be negative or greater than the precision. The maximum precision is 31 digits.
I am trying to round a value in SQL, here is the code that I have:
select round(600.000,2)
How do I get the value 600.00?
Instead of round() convert to a decimal:
select cast(600.000 + 0.5 as decimal(10, 2) )
round() changes the value but it might not change the type of the result. Hence, you might still see extra decimal points (depending on the database and the application). Converting to a decimal with two digits of precision converts both the value and the type.
I have a variable of type decimal(26,16) and i want to save a value with 12 digits before decimal point and 14 digits after it, but it raises an "Arithmetic overflow error converting numeric to data type numeric". when i define a variable of this type, what does it really mean? it means it can only store values with 10 digits before and 16 digits after decimal point respectively or something else?
The highest number you can have in a decimal(26,16) is 9999999999.9999999999999999.
So when you try to store a 12 digit number it will to overflow
Try a decimal(28,16) instead
The maximum total number of decimal digits that can be stored, both to the left and to the right of the decimal point. The precision must be a value from 1 through the maximum precision of 38. The default precision is 18.
precision means the maximum number of digit you can use.
scale means the maximum number of digit you can use after decimal(.)
refer this...
http://msdn.microsoft.com/en-us/library/ms187746.aspx
For a SQL int that is being converted to a float, how do I set the precision of the floating point number?
This is the selection I would like to truncate to two or 3 decimal places:
AVG(Cast(e.employee_level as Float))avg_level,
Thanks!
In TSQL, you can specify two different sizes for float, 24 or 53. This will set the precision to 7 or 15 digits respectively.
If all you want to do is truncate to a set number of decimal places, you can use ROUND, ie:
ROUND(AVG(CAST(e.employee_level as float)), 3)
As a general rule, you can't specify the number of digits after the decimal point for a floating-point number. Floating point data types store the closest floating-point approximation to any given value. The closest floating-point approximation is unlikely to have the number of digits you want. Although you might be able to suppress every digit after the third one, that will only change the appearance of the value, not the value itself.
Integers are a different story. An integer--stored, converted, or cast to a floating-point data type--will be stored exactly over a large range. Floating-point data types don't have to store any fractional units for integers.
I'd suggest, though that the best practice for you is to
avoid casting integers to floating-point if you don't need fractional units, or
cast integers to decimal or numeric if you do need fractional units, or
handle display issues entirely in application code.
I have had the same issue when calculating a percentage and needing a resulting string value.
Example: 68 is what % of 379
Result is a float = 17.9419525065900
You can cast/convert to Numeric with the Precision = 2 and get 17.94
If you need the value as a string you can then cast it as a VarChar if needed.
You can use Round() as well but in this case it only makes 17.9419525065900 = 17.9400000000000.
You can also use Ceiling() and Floor() to get the next highest or lowest integer.
Ceiling(17.9419525065900) = 18
Floor(17.9419525065900) = 17
Using these combinations you should be able to achieve a result in any format you need.